The VS, VS C and VS B series valves are butterfly-type valves. A circular valve plate with a sealing ring on the circumference rotates around an axis at right angle to the valve axis.
As a result, the valves leave virtually the entire cross section free, offering very good conductance. The valve bodies are made of one piece, machined from solid material, and require (in addition to the valve head seal) only one elastic shaft seal for rotational movement of the shaft. The valves provide low leakage and minimal degassing rate.
The VS C series features a valve seal made of perfluorelastomer material (FFKM).
PERFORMANCE FEATURES
- compact, economic design
- high conductance, low leakage rate
- gas-tight against atmosphere in both positions
- helium leak-tested
- easy to grip, lever-operated, with position indicator
